{"id":149,"date":"2021-05-18T11:20:34","date_gmt":"2021-05-18T11:20:34","guid":{"rendered":"http:\/\/habitatcdp.microwarecomp.com\/?page_id=149"},"modified":"2021-07-13T05:05:45","modified_gmt":"2021-07-13T05:05:45","slug":"soil-structure-soil-conditions","status":"publish","type":"page","link":"https:\/\/cdp.habitatindia.net\/ml\/soil-structure-soil-conditions\/","title":{"rendered":"Soil structure-Soil conditions"},"content":{"rendered":"
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Soil structure \/ Soil conditions<\/span><\/h1>\n

The topo-lithosequence of Kerala along with variation in rainfall, temperature and alternate wet and dry conditions particularly from\nthe western coast to high ranges in the east and swift flowing rivers lead to the development of different types of natural vegetation and soil.\nThe soils of Kerala can be broadly grouped into coastal alluvium, mixed alluvium, acid saline, Kari, laterite, red, hill, black cotton and forest soils.<\/p>\n

\nIn terms of geographical and soil conditions, Ernakulam district can be broadly classified into three physiographical units such as 1) Coastal Plains, 2)\nMid lands and 3) High lands. North Paravur Taluk falls under the category of coastal plains where the general elevation of coast is less than 8.0m.AMSL.\nThe major types of soil which is found in most of the regions of North Paravur Taluk are 1) silty clay, 2) silty sand and 3) laterite.<\/p>\n\n

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1. Single Grained Soil Structure<\/h5>\n

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Single grained structures are present in cohesion less soils like gravel and sand. The grains of cohesion less soils have less\nsurface force and more gravitational force. So, when we pour some amount of sand or gravel on the ground, the grains will settle\nusing gravitational force rather than surface force. After attaining the final position, each grain is in contact with\nthe surrounding grains and formed structure is called as single grained structure.<\/p>\n

\nThe single grained structure soils are deposited under gravitational forces but here the position of particles after settling also\nmatters. Let us assume that all the particles are spherical in nature then maximum void ratio (e= 0.90) is occurred when they\npositioned in cubical array manner which is as shown in figure and is called as loosest state of soil. Similarly, Minimum\nvoid ratio (e=0.35) will occur if they positioned in diagonal packing manner as shown in figure which is called densest state.<\/p>\n

\nIn general, the particles are not spherical in nature, but we can say that the void ratio of single grained particles is in\nbetween 0.35 to 0.90. To use soil for the civil engineering purpose, the void ratio of the soil should be minimum or in other words\ndense soil is preferable. Loose soil is very unstable and cannot withstand against vibration and shocks.<\/p>\n\n<\/div>\n

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2. Honeycomb Soil Structure<\/h5>\n

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Honeycomb structure found in soil contains particle of size 0.02mm to 0.002mm which are generally fine sands or silts. When this type of soil is\nallowed to settle on the ground, the particles will attract each other and joins one with another and forms a bridge of particles. A large void is\nalso formed between those bridges which makes the soil very loose in nature.<\/p>\n

The attraction of particles is due to cohesion between them, but this cohesion is just because of their size however, these soils are not\nplastic in nature. In fine sands, when water is added to dry fine sand bulking of sand occurs which is nothing but a structure of honeycomb.<\/p>\n

Honeycomb structured soil is limited for static load condition. They cannot resist vibrations and shocks under building and may cause large\ndeformations to the structure.<\/p>\n\n<\/div>\n

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3. Flocculated Soil Structure<\/h5>\n

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Flocculated structure is present in clay particles which contains larger surface area. These are charged particles which have positive\ncharge on the edges and negative charge on the face of the particle. When there is net attractive force between the particles, then positive\ncharged particles attracted towards negatively charged faces which results the formation of flocculated structure.<\/p>\n

Clay present in the marine area is the best example for flocculated structure. Salt present in the marine water acts as electrolyte and reduces\nthe repulsive force between the particles which leads to the formation of flocculent structure. This type of soils has high shear strength.<\/p>\n

Because of edge to face orientation void ratio is high in this type soil and water content also optimum but they are light in weight.\nThe compressibility is very low for this type of soils.<\/p>\n\n<\/div>\n

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4. Dispersed Soil Structure<\/h5>\n

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Dispersed structure also occurs in clay particles when the clay is remoulded. Remoulding reduces the sheer strength of soil which reduces the\nnet attractive forces between the particles. Hence, due to repulsion between them, the edge to face orientation turns into face to face orientation.\nFinally, dispersed structure of clay will form.<\/p>\n

This type of soil is highly compressible and less permeable. The loss of strength during Remoulding is slowly achieved by the soil with the time.\nThe process of regaining its strength after Remoulding is called thixotropic.<\/p>\n\n<\/div>\n

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5. Coarse Grained Skeleton Soil Structure<\/h5>\n

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Coarse grained skeleton is a structure of soil which is present in composite soils containing both fine and coarse-grained particles.\nBut, it is formed when there is large amount of coarse grained particles than the fine-grained particles.<\/p>\n

The coarse-grained particle forms a skeleton like structure and voids between them are\nfilled by fine grained or clayey particles. If it is undisturbed, it will give good results against heavy loads. If disturbed,\nthe strength extensively reduced.<\/p>\n\n<\/div>\n

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6. Clay Matrix Soil Structure<\/h5>\n

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Clay matrix structure, which also occurs in composite soils, but the amount of clay particles or fine-grained particle, is more compared to\ncoarse grained particles. Coarse particles in this soil are separated with each other as they are less in quantity. This type of soil is very\nstable in nature and it has same properties of an ordinary clay deposit.<\/p>\n\n<\/div>\n

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Map of North Paravur Taluk indicating soil conditions in various Panchayats<\/p>\n\n<\/div>\n<\/div>\n

Vadakkekara<\/b> is one of the plain regions. Soil in this area is alluvium. During high tides and low tides, the water from\nsea will enter in to the shallow streams in rural areas. Vadakkekara Panchayat is surrounded by tributaries and related\nstreams by Periyar. The lack of caution in protecting them has a profound impact. Chittattukara<\/b> is a coastal plain and\nhave coastal alluvial soil.<\/p>\n

\nDepending on the geographical area, the area under Kottuvalli<\/b> Panchayat can be divided in to four categories 1) High plains, 2)\nSlope area, 3) Coastal plain. 4) Swamps. Kaitharam and Kottuvally portions consist of sandy soil and mud. The eastern part,\nThathapilli is muddy soil and northern part is clayey soil. Valluvally koonammavu is composed of sandy soil. Kottuvally gram\nPanchayat is also known as agro climate zone and costal sandy zone.<\/p>\n

\nBased on the geographical features Ezhikkara<\/b> Gram Panchayat can be divided into 3 categories such as 1) Coastal plain, 2)\nLower pokkali fields, 3) Swamp and water logging area. The area consists of coastal alluvial soil. The unprecedented flood\nhas caused so many alluvial soil to deposit within the Panchayat boundaries.<\/p>\n

\nChendamangalam<\/b> is a village with lots of rivers and streams. The Kottayil Kovilakam is the highest region in the Panchayat and\nthe soil of this area is laterite. Rest of the areas have Red soil.<\/p>\n

\nThe Karumalloor<\/b> Panchayat belongs to the midland region. It can be classified into four regions according to the geographical\narea. 1) High planes area, 2) Slope area 3) Coastal plain 4) Swamps. Manjali, Muttankunnu, Karukkunnu, Valyappanpadi, Thudalukunnu\nthese are the high planes area in the Panchayat. Among these Muttankunnu is the highest plane. Silt soil, which is suitable for\nfarming is seen in low lying areas of Muttankunnu. The north-east side of Aluva-Paravur road, V H Colony, Settlement are high slope\narea with Laterite soil. Thudalikkunnu is a high plane area with slopes and Laterite soil. On the South part, it is Clay like soil.<\/p>\n

\nThe north part and middle area is laterite soil. On the north-west area it is silt soil. On the west of Millupadi is high plane\narea with slope.\nThe Attippuzhakkavu area is Farmlands. Some area has mixture of laterite and clay, mostly in coastal area. Veliyathunad, Paruvakkad,\nAduvathuruth are suitable for agriculture, marshy lands are also seen here. Karumalloor, Kallarakkal areas are plains, but\nThattampadi-Angadikadavu road have marshy areas. These are normally farmland with silty soil. On the northern side of Aluva-\nParvoor road is entirely of muddy farms. Thattampadi- Thanthoni, Chalil, Panatt are of flat plain area. Mundeppadam, the northern\nside of Aluva-Paravur road is farmlands. North-south side have silt soil whereas on the east side there is a mixture of silt soil\nand marshy lands, and the west lands is of sandy area. Chettikkadu, Puthukkadu are of flat plain areas. Thaithathara is a coastal\narea. South side of this area is marshy lands. Manakkappadythoppu is little high plane area. Anachal area is of swamps. Most of\nthe area is of sand mixed soil. Manakkappady- Muriyakkal are of flat plane areas. On the side of Manakkappady-Mandala road have\nmarshy land. North-west\u00ad east have sandy mixed soil and south part have clayey soil. Manjali – Kunnumpuram is also a high plane area.\nMost of the areas are with slopes. On the east have laterite soil and centre had a mix of sandy soil and northern area has rocky\nsand, south-west area have sandy mixed soil.<\/p>\n

\nThe geographical area of Puthenvelikara can be classified in to three namely, 1) Hilly areas 2) Plain areas, 3) Coastal areas.\nManacherikunnu, Kappelakunnu, Paramanasharikunnu, Enjarakunnu, Thuruthoor, Panachakunnu, Vattekattkunnu, Kodikuthiyakunnu are\nthe major hills in the village. Red colour laterite soil is found in these hilly areas, sandy black soil and alluvial soil are\nfound in plain areas and coastal areas. The soil here is so fertile.\nAlangad and varapuzha is surrounded with rivers and have alluvial soils.<\/p>\n\n

Characteristics of each type of soil<\/h5>\n

The type, depth and size of a footing depends on the bearing capacity of the supporting material (soil or rock), which again\ndepends on the type of soil and many other factors such as soil structure and composition, ground water etc. Common types of\nsoil, their bearing capacity properties and the type(s) of foundation suitable for each soil type are given below;<\/p>\n

\n1. Rock –<\/b> Rock usually offers a high bearing capacity, which depends on the type of rock, state of weathering and any fissures\nthat exist within the rock In certain areas, rock may exist at shallow depth. Reinforced pad footings for columns and narrow\nstrip footings for walls would be quite adequate on rock On a slope rock surface, the foundation may have to be doweled in to\nthe rock Besides rock, there are five other types of soils having particles of different sizes, which may naturally exist in\ndifferent compositions.<\/p>\n\n

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2. Gravel and Gravelly Soils –<\/b> Gravel, sometimes mixed with small pro\u00ad portions of sand\/ or clay etc.,\nexist as gravelly soils. As they have a low compressibility and a high bearing capacity, pad footings can be used for columns\nand strip footings for the walls.<\/p>\n\n

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3. Sand and Sandy Soils –<\/b> Sandy soils also have a high bearing capacity when densely compacted, but, relatively\nlow bearing capacity when loose. Dense sandy soils have low compressibility but foundations placed on loosely compacted sandy soil\ncan undergo significant settlement quickly as the load is applied. Pad footings for columns and strip footings for walls can be used.\nSettlements in sandy soils will be completed within a short time, mostly during construction.<\/p>\n

4. Silts and Silty Soils –<\/b> Silty soils have a moderate bearing capacity when dry, compacted and confined. But,\ntheir structure can easily break down when exposed to water. Silty soils are compressible when loose. Pad footings or strip footings\nof appropriate size can be used in silt soils as column and wall foundations respectively.<\/p>\n

5. Clays and Clayey Soils –<\/b> Clayey soils are made up of fine particles and are described as cohesive soils for their\nsticky and binding properties. They generally have a lower bearing capacity than the sandy soils. Foundation load can cause significant\nbut gradual and prolonged settlement in some clay, which may occur over weeks and months or even years. Some clay has a very high affinity\nfor water and expands with the absorption of water.<\/p>\n

6. Organic Soils –<\/b> Organic matter may exist alone as in peats that are highly compressible or mixed with clays,\nsilts or sands. Foundations should be avoided on organic soils without appropriate ground improvement.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"Soil structure \/ Soil conditions The topo-lithosequence of Kerala along with variation in rainfall, temperature and alternate wet and dry conditions particularly from the western coast to high ranges in the east and swift flowing rivers lead to the development of different types of natural vegetation and soil. The soils of Kerala can be broadly […]","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-149","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/pages\/149","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/comments?post=149"}],"version-history":[{"count":87,"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/pages\/149\/revisions"}],"predecessor-version":[{"id":2776,"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/pages\/149\/revisions\/2776"}],"wp:attachment":[{"href":"https:\/\/cdp.habitatindia.net\/ml\/wp-json\/wp\/v2\/media?parent=149"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}